1. Field of the Invention
The present invention relates to a nitride semiconductor device, and more particularly, to a nitride semiconductor device capable of enhancing light emission efficiency by alleviating thermal stress and lattice stress acting on an active layer.
2. Description of the Related Art
Nitride semiconductors are broadly utilized for green or blue light emitting diodes (LEDs) or laser diodes (LDs), which serve as the light sources of, for example, full-color displays, image scanners, various signal systems and optical communications devices. The nitride semiconductor devices may be provided as light emitting devices including active layers that emit light of various colors, such as blue and green, by electron-hole recombination.
Since the development of nitride semiconductor devices, technical advancements to broaden their application ranges have been made. Thus, many studies are being conducted to determine how to utilize nitride semiconductor devices in general lighting apparatuses and electrical lighting sources. According to the related art, nitride light emitting devices have been used as components employed in low-current, low output mobile products. However, of late, the application ranges of nitride light emitting devices have been broadened to the field of high-current, high-output products. This has led to a need to enhance light emission efficiency by improving the quality of nitride semiconductor crystals and the like.